Reloading: To Crimp or Not to Crimp, That is the Question

in Authors, GA Guides, Getting Started, Metallic, Reloading, Reloading Guide, Tom McHale
We're going to use a weird analogy to illustrate what crimping does and does not do. It's kind of like inserting a wooden dowel into a hole drilled in a block of wood.

We’re going to use a weird analogy to illustrate what crimping does and does not do. It’s kind of like inserting a wooden dowel into a hole drilled in a block of wood.

Reloading: To Crimp or Not to Crimp, That is the Question

This Hornady taper crimp die removes the flare from the case mouth. Image courtesy of Hornady.

SERIES:

Crimping gets a bad rap.

Just as we sometimes tend to fix construction mistakes with a hammer rather than taking the time to properly fit parts, we tend to view crimping as a way to “fix” a less than perfect bullet seating. The problem with crimping is that it sounds so logical. The word “crimping” kind of implies the process of locking a bullet in place.

We know that a bullet has to be firmly seated in a cartridge. If a bullet is too loose, it can move during recoil or in extreme cases, fall out of the cartridge altogether. If a bullet in a magazine or cylinder moves partially out of the cartridge case during recoil, it can jam up the works. In a revolver, that may prevent the cylinder from turning. In a semi-automatic, that cartridge might cause a feeding jam. On the other hand, if a bullet gets pushed farther into the case, it can increase pressures to catastrophic levels. As the bullet gets pushed in, there is less internal case volume, and when you touch off that round, less volume means higher pressure. How much higher depends on the specific load and amount of bullet setback.

As a result, it’s important to make sure that projectiles are seated firmly and properly in the cartridge case. The gotcha is that crimping is not the way to do this, with a few partial exceptions that we’ll discuss in a bit. The short explanation is that crimping is not what keeps a projectile firmly seated, case neck tension is, and those two things are not the same. Likewise, crimping doesn’t create or even restore case neck tension. Let’s explore the whole case neck tension thing a bit more.

Case Neck Tension Explained

A good way to understand the concept of case neck tension is to drill some holes in a 2×4 board.

Imagine we have a standard piece of 2×4 lumber. We’re going to drill some holes and stick wooden dowels in them. In this analogy, the board is our cartridge case, and the wooden dowels are the projectiles. Our goal is to make sure that the dowels are stuck in those holes in the 2×4 really tightly so they can’t be pulled out too easily. For this example, assume that our dowels are exactly 1/4” in diameter. We can drill the holes exactly that size, a little smaller, or even a little bigger if we like. Likewise, when we flare case mouths (analogous to drilling the hole in our 2×4) in cartridge cases, we can do it a little or a lot.

For starters, let’s assume we drill a 3/16” hole. That’s a hair smaller than the dowel diameter, so we’ll have to force the dowel into the hole. As we do this, the dowel will compress a bit, and the size of the hole will expand just a hair. The result is a very tight fit. It’ll take a lot of work to get the dowel into position, but once it’s in place, it’s going to take a lot of force to remove it. You can think of this like case neck tension. Since the dowel and hole are tightly mated, there’s a lot of friction between the two surfaces – the exterior of the dowel and the interior walls of the hole. If we seat a bullet the same way, but with much closer dimensional variances, there will be a similar result. The bullet surface and inside of the cartridge case will be tightly joined, and you’ll have to overcome a lot of friction to pull that bullet out. Make sense so far?

If we want to "seat" this wooden dowel so that it doesn't move in or out, drilling a slightly smaller hole will do the trick.

If we want to “seat” this wooden dowel so that it doesn’t move in or out, drilling a slightly smaller hole will do the trick.

Now let’s imagine the opposite scenario. If we want to take the easy way to “seat” the dowel in the hole, we can drill a larger hole, say 5/16” and the dowel will just drop into place. You’ll be able to remove and reinsert the dowel with ease since the sides of the dowel and interior of the hole basically don’t contact each other. If you want the dowel to be tightly “seated” you can just “crimp” the dowel into place, right? If you stick the 2×4 into a giant vise and compress it from the sides, it should press the sides of the hole against the dowel, thereby making a really unusual wood crimp. I think we can all agree that’s not going to work out too well. No matter how much you squash the sides of the 2×4, even to the point of mashing the sides of that 5/16” hole firmly against the dowel, it’s not going to hold. Compressing the sides of the hole against the dowel simply won’t create the same degree of friction as our first example.

Can we agree that "crimping" this dowel into place with a vise isn't going to be effective no matter how much we squeeze the vise?

Can we agree that “crimping” this dowel into place with a vise isn’t going to be effective no matter how much we squeeze the vise?

With most materials, it’s impossible to recreate the tension created by stuffing a larger object into a smaller hole by pressing on the sides of the hole. When you seat a bullet into a cartridge case that has too large an interior diameter, the same thing happens. You can squeeze that case all you want, and the bullet will never be tightly seated. In fact, you can squeeze so much that you actually reduce the tension, making the bullet fit even looser than before you started crimping. Or, you can deform the bullet, leading to all sorts of wonky shooting results.

There is one “partial” exception – roll crimping – and we’ll talk about that in a minute. However, even in that example, it’s important to get proper case neck tension even before you think about applying that roll crimp.

Before we discuss the two most common types of crimps, we need to understand the concept of headspace. It’s a big topic all on its own, so for now, just think of it this way. A cartridge needs to sit in a chamber or cylinder in just the right position away from the firing pin. It needs to stay put so that when the firing pin strikes it, the impact doesn’t simply push the cartridge forward. Different calibers use different means of controlling headspace, and that impacts that type of crimp that can be used.

Straight wall pistol cartridges like 9mm, .40 S&W, and .45 ACP use the edge of the cartridge case mouth to control headspace. If you look in the chamber of a pistol barrel, you’ll see a little ledge. The case mouth jams up against this ledge, preventing the cartridge from moving forward. If the case is the right length, headspace is controlled.

Straight wall pistol cartridges like these use the case rims for headspace, so only a taper crimp can be used.

Straight wall pistol cartridges like these use the case rims for headspace, so only a taper crimp can be used.

Revolver cartridges like .38 Special, .357 Magnum, and .44 Magnum headspace using the rim on the base of the cartridge. That rim is what stops the case from moving farther into the cylinder.

Most revolver cartridges use roll crimps like these. If you look closely, you can see where the case mouth is slightly turned into the bullet cannelures.

Most revolver cartridges use roll crimps like these. If you look closely, you can see where the case mouth is slightly turned into the bullet cannelures.

Many rifle cartridges headspace using the shoulder of the cartridge case. That part where the case narrows to projectile diameter jams up against its mate section inside the chamber to position the cartridge correctly.

Roll Crimping

Roll crimping refers to the process of pushing (rolling) the cartridge case mouth edge into a groove called a cannelure that’s cut into the bullet. The edge of the cartridge case “digs” into a groove in the bullet, helping to prevent forward or backward movement. You can use roll crimping on cartridges that headspace on the rim or shoulder of a bottleneck cartridge case because the cartridge case mouth edge is not relevant to proper headspacing. Simply put, a “ledge” on the cartridge case mouth is not needed. You’ll also notice that many military cartridges use some variation of a roll crimp as well. Since those headspace on the shoulder, a roll crimp can be used to help make sure the bullet doesn’t move under recoil. Cartridges destined for use in machine guns often use this type of crimp.

Bottleneck cartridges that use the shoulder for headspace can use taper crimps, roll crimps, or mashed-up roll crimps like the one in the center.

Bottleneck cartridges that use the shoulder for headspace can use taper crimps, roll crimps, or mashed-up roll crimps like the one in the center.

Taper Crimping

Taper crimping really isn’t crimping at all, at least in the commonly understood sense of the word. Think of taper crimping as the process of gently squeezing the cartridge case mouth back into its normal position once a bullet is seated. As we discussed earlier in the series, before seating bullets into straight wall cases like 9mm, you need to ever so slightly flare open the cartridge case mouth to make room to start a bullet seating. After the bullet is seated, the taper crimp gently pushes that flare back to original dimension. Taper crimping really does not do much to increase the tension between the case and the bullet. Consider the wooden dowel example we discussed earlier. In fact, too much taper crimp pressure can squash the projectile, loosen brass case neck tension, and make that bullet less secure than before you started.

So, back to the basic question of “to crimp or not to crimp,” the answer is yes – with qualifications. The type of crimp will be determined by the cartridge you’re reloading, so that’s an easy decision. The important thing to remember is that crimping is not a corrective technique for sloppy seating. Finding the right degree of case mouth flaring will help you achieve proper case neck tension so the crimp can do what it’s supposed to do and nothing more.

About the author: Tom McHale Literary assault dude writing guns & shooting books and articles. Personal accountability rocks!

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  • Yosemitebam October 12, 2020, 7:07 am

    So would a good taper crimp work alright in old 375 Win leveraction rifle

  • Bobby January 24, 2020, 4:02 pm

    Omg you people dont understand the word straight.

    People think if two straight lines are not parallel then they must not be straight?

    What? They become round or elliptical?

    Example a triangle is made up of three straight lines/walls. Even though they are not parallel the walls are all straight.

    Same goes for anything not just cartridges. Geeze.

    9mm and 450 bushmaster are both straight walled and yes they have non parallel sides.

    Get it????

  • Bobby January 24, 2020, 3:16 pm

    crimping is almost always a corrective measure on straight wall cartridges if you flair the opening. That flair has to be pressed flat or it wont fit all the way into the chamber.

    I would just leave it as a taper crimp reverses the flare you put on the cartridge.

    It does add tension too. Put too much flair on oown ng and the bullet will be looser for sure.

  • Jay June 1, 2017, 8:16 am

    Wowsers, stirred up a lot of opinions and facts too!. Nearly all Factory ammunition has a crimp according to the type of ammunition that it is by design. If you’ve been a round as long as I have, some of the older factory ammunition actually had another crimp at the base of the bullet (serrated shoulder) on the case, on magnum cases especially, to prevent bullet set back! I never questioned weather to crimp or not to crimp. Crimp to a cartridge is like water to a duck, you crimp. The bottom line is, follow your loading dies recommendations and do it properly and you’ll have no problems!

  • Abnormal June 1, 2017, 12:50 am

    I read this article twice and your wood analogy just doesn’t work. There is so much difference with the way wood reacts to expansion and contraction and the way brass metal works that the two are apples and oranges. The case mouth has to be expanded to get the bullet to seat without damaging it. Once it is seated to the proper depth it then needs to be case crimped back to the proper state to hold the bullet in place and chamber properly without hanging up on the case mouth. The key to crimping the case mouth is to NOT over crimp it. Over crimping will cause too much case pressure. Under crimping, well, you explained that right. The bullet can move around causing unexpected pressures or even catastrophic results including squib rounds. The key to crimping is to get it right and don’t change it after. Crimp it just enough and don’t give it that “little extra” just for good measure.
    I use the Lee dies and quick change bushings. Once the dies are set up, put the bushing on and tighten it to the die. You never have to change it after that. Lee offers pretty good videos on setting them up but the crimp dies are not explained very well for rifle loading. The pistol crimp dies are simple and adjustable. Rifle crimp dies are not as easy for some reason (different design engineer). Just don’t over crimp and you should be OK. Just remember that brass doesn’t react the same as wood when stuffing a round object into a round hole.

  • bjg May 29, 2017, 9:20 pm

    Where did you find such a horrible looking cast bullet for this story?

  • Richard Downing May 29, 2017, 11:41 am

    My question is I just bought an Ruger American Ranch Rifle in 450 Bush Master and using the Hornady 250 gr. FTX bullet. I have been using the taper crimp so far because the have no cannelure but I’m going to load some Hornady 225 FTX’s witch have a cannelure, what would you recommend I use on the different bullets?

    Thanks,
    Richard Downing

    • AKB May 29, 2017, 2:11 pm

      450 Bushmaster headspaces on the case mouth, so you should ALWAYS use a taper crimp, regardless of whether you use a cannelured bullet or not. And as always with a taper crimp, only crimp enough to remove the mouth flare. Do not over crimp. Do not attempt to roll crimp, as this will cause headspacing issues that may result in ignition problems (light primer strikes).

  • Sgt. Pop May 29, 2017, 10:40 am

    If you can’t push the bullet further down with your fingers, probably ok in a revolver as stated above, however, if you shooting “cowboy” loads with FMJ, don’t show up at a SASS shoot as only Lead is allowed.

  • James Drouin May 29, 2017, 10:29 am

    There was so much misinformation in this article, it should never have been published.

    First of all, the analogy was incorrect … pistol case reloading use an expander die on the case mouth, opening the case mouth slightly (which allows the bullet to be seated with its axis correctly oriented), thus must be crimped back down to hold the bullet in place.

    Secondly, forward movement of a cartrdge into a firearm chamber is always, ALWAYS, controlled by the extractor assembly, and a simple review of SAAMI specs shows that pistol cases are shorter than chamber head space (rimmed cases, aka virtually all revolvers headspace on the rim, but case length is still shorter than chamber length). A similiar review of bottleneck cartridge dimensions also show that cartridge headspace is shorter than the corresponding chamber dimension.

    Third, crimping on ‘bottle-neck’ rifle cartridges is a function of the firearm they will be used in (straight-walled rifle cartridges are treated as pistol cartridges, thus must be roll- or tarper-crimped). If the cartridge is to be used in a bolt-action rifle, and the cartridge was properly loaded, then crimping is not required. If, on the other hand, the cartridge is to be used in a semi-automatic firearm, then crimping is almost certainly required. The reason for the difference is inertia (Newtons First Law); a cartridge being loaded into a bolt-action firearm imparts almost no inertia into the projectile as the cartridge comes to a stop into the chamber. That same cartridge being loaded into a semi- imparts an enormous amount of inertia into the projectile and, when the cartridge comes to a sudden stop, the projectile – in accordance with Newtons First Law – wants to keep moving and will almost certainly unseat or loosen from the case (this lossening is not only highly unsafe, but has a drastic, i.e. “not good”, effect on firearm accuracy.

    • AKB May 29, 2017, 3:28 pm

      There is so much misinformation in this comment, it should never have been posted.

      • James Drouin May 29, 2017, 9:54 pm

        AKB – When you get over your hurt feelings, feel free to point out the ‘misinformation’.

        • AKB May 30, 2017, 9:07 pm

          Sure no problem. I’ll condense this response as much as possible.
          Point #1- The function of the expander die. The article above attempted to explain neck tension with a dowel in a block of wood…we could debate whether this was an effective analogy or not, but the article failed to explain is that neck tension is always the most important factor for keeping a bullet in place. When brass is sized, the neck ID is purposely squeezed down smaller than the OD of the bullet to be seated, by several thousandths of an inch. This is to create a press-fit between the bullet and the case. It takes a pretty significant amount of force to seat a bullet, but it doesn’t seem like it because our reloading presses provide us with mechanical leverage to help with the task. Most straight wall cartridges come with an expander die primarily because the design of the bullets that are to be seated are usually flat based, usually with a pretty sharply squared bottom edge. The case mouth needs opened up to allow easy entry of the bullet, and prevent mashing the case. The plug inside an expander die has a rounded bottom to guide it into the undersized case mouth, a somewhat short cylindrical shank, and then tapers up to a larger OD. The taper provides the mouth flare. The short cylindrical shank below the taper is still several thousandths smaller than the bullet OD to preserve the desired press fit and neck tension. Most all of the bullet shank is seated down in the undersized, tight neck of the brass below the flare and is providing all the force needed to hold the bullet in place. The only reason to taper crimp is to bring the very short section of expanded mouth back to spec by removing the flare. Not to hold the bullet in place.
          Point#2 – Forward movement of the cartridge is not always, ALWAYS arrested by the extractor assembly. This is true for many modern bolt actions and semi-auto rifles. Anyone who owns a push-feed bolt action like a Rem 700, post ’64 Win model 70, Howa 1500, or a host of many other bolt guns can attest to this. Semi-auto rifles are also nearly all push feed systems, they just do the job for you. The round is stripped from the magazine by the bottom edge of the bolt, slid up the feed ramp, and rammed into the chamber. Once the forward motion of the round is stopped in the chamber by it’s headspacing feature, the extractor is able to snap over the rim as the bolt locks. The round is not under the extractor until it is already chambered. One notable exception to this rule in the world of rifles are Mauser style controlled round feed bolt rifles, which the non-rotating extractor claw captures the cartridge rim as it strips it from the magazine. Semi-auto handguns also function basically the same way. But the forward motion is still stopped by the headspacing feature of the cartridge. If so desired, one can load a single round in a semi auto handgun without feeding it from the magazine…lock slide back, drop in round, and release slide. The round can’t move forward because of the headspacing feature, not because of the extractor. Of course case dimensions are always smaller than corresponding chamber dimensions…they have to be (and within a tolerance), otherwise the round would never chamber.
          Point#3 – Inertia effects. Bullets can certainly be moved from inertial effects, and a perfect example is inertial (hammer style) bullet pullers. Heavy recoiling cartridges (such as magnum revolver cartridges) fired from light weight weapons (such as titanium or scandium) can experience outward movement of bullets. To counter this, the cartridges are often given a strong roll crimp to help make sure the bullet stays put. Sometimes the cartridges can move out far enough to prevent cylinder rotation. This is known as “crimp jumping” and can be a real pain in the neck. However, I have never observed nor have I ever heard of any such inertial effect in a semi-auto firearm (or any firearm) caused by function of the weapon on un-roll crimped ammunition. They simply don’t move the ammunition with enough speed and force. If I had never fired anything in a semi-auto rifle besides roll crimped ammo, then I might believe maybe that’s why they are roll crimped. But I’ve fired hundreds upon hundreds of non roll crimped ammo in semi auto rifles, and never had any bullets move. I can take some un-roll crimped ammo, chamber it in a semi auto rifle over and over again, measuring each time, and the bullet won’t move – OAL never changes.

          • James Drouin May 31, 2017, 10:40 pm

            Well, AKB, let me point out where you’re “wrong”.

            Point 1: As a rimmed rifle case or semi-rimmed or rebated rimless pistol case is processed into a cartridge all, ALL those die types “expand” the case mouth. As the bullet is seated all, ALL those die types “crimp” the case mouth closed to firmly hold the bullet in place. There is no, NO choice involved in whether or not to crimp a rimmed rifle case or semi-rimmed or rebated rimless pistol case … that is part of the die’s operating function. And it’s not an optional function, it is built into the die.

            Point 2: Your assertion that the extractor spring rides over the rim after the cartridge is seated merely confirms your lack of knowledge on how a cartridge cycles, how an extractor functions, and what the major change is extractor design was. To begin with, the rim of the case slides UNDER the extractor as a case feeds into a semi-automatic firearm from a magazine and the rim is fully engaged by the extractor prior to the cartridge being fully chambered. Mitigating damage an extractor incurs by riding over a rim, such as when a cartridge is loaded into an opened semi-auto pistol and the slide is released is THE reason John Browning’s full-length extractor design has been (mostly) replaced by extractors which pivot.

            Point 3: The type of crimp applied to a cartridge’s case is 100% dependent on the type of case the cartridge is constructed from; rimmed rifle case-type cartridges and semi-rimmed pistol case-type cartridges always, ALWAYS, use a roll type crimp and rimless and belted rimless rifle case-type cartridges along with rebated rimless pistol case-type cartridges always, ALWAYS, use a taper crimp.

            Thus, a roll type crimp will never, ever, EVER be found on cartridges such as .380 auto, 9mm luger, .45 ACP or on ANY rifle cartridge that uses rimless or belted rimless type cases, all the way from the .22 Hornet through to the .338 Lapua.

            Additionally, while I’m not intimately familiar with ALL of the world’s automatic or semi-automatic rifles, I know for a “fact” that you have never, ever, EVER, fired a Thompson submachine gun, Bren gun, Grease gun, M1 carbine, M1 Garand, M14, any M4 type, any .223 type, any AR10 type, or any AK type with cartridges that used roll type crimps … NOT EVEN ONCE BECAUSE THE AMMUNITION FOR THOSE FIREARMS DO NOT, HAS NOT, AND CAN NOT USE ROLL TYPE CRIMPS. So, your assertion on semi-automatics using roll type crimps is either pure delusion or worse.

      • Ryan May 29, 2017, 9:56 pm

        Gonna back your comment up, or just another keyboard quarterback? I found the 1st part of the comment just a reiteration of the OP, the 2nd part accurate, and the 3rd part a matter of opinion. For example, I’ve personally loaded thousands of .223, typically with a cannelured 55gn FMJBT and I don’t ever crimp them, keep them loose in an ammo box bouncing around. I’ve never had (and I’ve spot checked for it) “transit runout” or accuracy problems.

        • Richard May 30, 2017, 2:30 pm

          This is all opinion. I have shot thousands of 30-06 in M1 Garands with no crimping. I have shot tens of thousands of .223/5.56 without crimping. I only crimp my revolver loads with a roll crimp and use taper with semis. So there are no musts or have tos. And when someone with a lee factory crimp ( whatever the hell factory crimp is as they are all different) says crimping gives better accuracy then I’ll see you on the bench and bring some cash.

          • Alan May 31, 2017, 3:52 pm

            AAAND that last comment is a matter of opinion too, as I have used the Lee crimp on several different cartridges and found that in many cases it did indeed increase the accuracy.
            In the case of my 6mm HB Varmint rig, my load went from printing .55inch 5 shot groups to .44 inch groups.
            Just by using the Lee crimper.
            Tested three times from a Lead Sled, that proved the point for me.
            But hey, just as there are ‘experts’ in every human endeavor, so are there here, eh?

  • gordon May 29, 2017, 10:02 am

    RE: John. 9mm Luger is not a straight walled cartridge??? I must have been reloading the wrong brass for the past 40 years and did not know it.

    • Ralph May 29, 2017, 10:38 am

      John is correct. The 9MM is tapered. It is .380″ at the mouth and .391 at just above the rim.

    • Ken May 29, 2017, 11:07 am

      9mm is a straight-wall cartridge per paragraph 11 of the article.

    • Mike May 29, 2017, 1:09 pm

      John was referring to the fact that the 9mm para case tapers slightly outward at the base as opposed to the 40S&W and 45ACP who’s case walls run almost perfectly parallel to each other the entire length of the case.

    • AKB May 29, 2017, 2:00 pm

      Yes, the case of 9mm Luger has a very slight taper…but in reloading terms, it is “straight walled” because there is no shoulder of any significance. So John is technically correct, but not in context of the article, so I’m with you on this one Gordon.

  • Skip May 29, 2017, 7:28 am

    I highly recommend the Lee factory crimp dies. They crimp via a collet. On cartridges that head space on the case mouth they are much better than a taper crimp.

    • AK May 29, 2017, 10:39 am

      After hearing for years from several friends how “9mm was impossible to reload” I had to give it a try. Got a load of mixed brass, a Lee 124 grain truncated cone tumble-lube mold, and Lee dies for my RCBS Piggyback. Made up a few dummy rounds (Alox, unsized) and they feed very nicely in my vintage Browning HP. Cranked out 100 rounds yesterday (3.6 gr 231) and hoping for a range test today. I set a tight crimp and they do seem to have “rolled” a bit on the case mouth.

  • John May 29, 2017, 6:43 am

    Good article with one correction, 9mm Luger, as shown in the picture, is not a straight walled cartridge.

  • Dr. Strangelove May 29, 2017, 5:26 am

    Also, if too much taper crimp is applied, the bullet will compress and the brass will spring back slightly, leaving the projectile loose.

  • Ron Schneider May 23, 2017, 1:53 pm

    Truly one of the Best Articles I have read to Explain about Crimping! Good for Novice & Experienced alike.

    • bison1913 May 29, 2017, 3:34 pm

      I am quoting James Drouin… and if I were you I would take his advice. One of the worst examples or analogies given on crimping for reloads. Just so much misguided information.
      “There was so much misinformation in this article, it should never have been published”.

      First of all, the analogy was incorrect … pistol case reloading use an expander die on the case mouth, opening the case mouth slightly (which allows the bullet to be seated with its axis correctly oriented), thus must be crimped back down to hold the bullet in place.

      Secondly, forward movement of a cartrdge into a firearm chamber is always, ALWAYS, controlled by the extractor assembly, and a simple review of SAAMI specs shows that pistol cases are shorter than chamber head space (rimmed cases, aka virtually all revolvers headspace on the rim, but case length is still shorter than chamber length). A similiar review of bottleneck cartridge dimensions also show that cartridge headspace is shorter than the corresponding chamber dimension.

      Third, crimping on ‘bottle-neck’ rifle cartridges is a function of the firearm they will be used in (straight-walled rifle cartridges are treated as pistol cartridges, thus must be roll- or tarper-crimped). If the cartridge is to be used in a bolt-action rifle, and the cartridge was properly loaded, then crimping is not required. If, on the other hand, the cartridge is to be used in a semi-automatic firearm, then crimping is almost certainly required. The reason for the difference is inertia (Newtons First Law); a cartridge being loaded into a bolt-action firearm imparts almost no inertia into the projectile as the cartridge comes to a stop into the chamber. That same cartridge being loaded into a semi- imparts an enormous amount of inertia into the projectile and, when the cartridge comes to a sudden stop, the projectile – in accordance with Newtons First Law – wants to keep moving and will almost certainly unseat or loosen from the case (this lossening is not only highly unsafe, but has a drastic, i.e. “not good”, effect on firearm accuracy.

      • AKB May 29, 2017, 8:40 pm

        The only thing more retarded than what James Drouin wrote is the fact that you believed it and re-posted it.
        There is practically nothing in his comment that is correct. I’m not a big fan of this article or the analogies they attempted to use, but there is more truth in the article than anything Mr. Drouin said. I’m not trying to be a dick, but I get so sick of people posting their ridiculous theories and presenting them as if they are undisputed fact.

        • James Drouin May 30, 2017, 8:34 am

          AKB – So, still stuck on your hurt feelings … again, if you can get past those, feel free to pont out the incorrect parts.

  • Mark N. May 23, 2017, 1:20 am

    Being only a novice, the only thing I know about roll crimping is that it makes my cowboy loads cycle much better in a lever gun. And look more authentic too. My problem is this: I have a bunch of .45 colts that were not properly neck tensioned by the manufacturer. It probably isn’t much of an issue, since these rounds have a very small amount of smokeless in them, and the round is a low pressure round to begin with. the question is, is there is a way to correct that issue without unloading and reloading every single round? I think it probably could be done with a single stage loader, but if I’d have to pull all the bullets and start over from a primed case, it is probably more trouble than it’s worth.

    • Tom May 23, 2017, 10:10 am

      Without seeing them, I have to be careful about recommending anything, but the first question I would ask is are the bullets moving back and forth in the cases? Can you knock on on the bench, bullet first, without the bullet moving back into the case?

      You can probably help the situation a bit by applying a roll crimp if there isn’t one already and that may help depending on how bad the situation is.

      Again, not seeing them, I would take a safety first approach and if they are moving back into the case and a roll crimp doesn’t help, I would pull the bullets and start over or dispose of them if you can’t do that. Hopefully it’s not a large quantity 🙂

      • Mark N. May 23, 2017, 10:12 pm

        Thanks. I tried roll crimping, but these are FMJs with no cannelure, and the attempt seemed to have no effect. They are not moving a lot, but I don’t like any movement at all. They will not shake out and take a few good wacks to pull.
        I do have some factory rounds that can all be easily, if tediously, roll crimped with my Lee Loader. (I started small, planning on reloading only the .45 Colts.)

        • AKB May 29, 2017, 1:48 pm

          Mark,
          Strange things are afoot here. It is extraordinarily odd for any factory to produce .45 colt loads with un-cannelured bullets. In handguns, any bullet without a cannelure is intended for use in an auto pistol (rimless case, taper crimp), and conversely, any bullet with a cannelure is intended for use in a revolver (rimmed case, roll crimp). While it is common for handloaders to mix ‘n’ match bullet designs and cartridge designs for various reasons (usually cost or availability of bullets), it is very strange (almost unheard of) for any factory to do so. Regardless, there is nothing wrong with the practice, as long as they are loaded properly with the correct dies. In this case, things were obviously not done correctly, whoever made them.
          Are they worth saving? Hell yes! You are a reloader now…this is our bread and butter! Welcome to the brotherhood. But I can understand why you don’t relish the idea of hammering each round apart. I started out with a hammer puller too, and they suck. I highly recommend you get yourself an RCBS collet bullet puller and a .45 collet. They make the disassembly process much easier, cleaner, faster, and if you have more than just a few to pull apart, you can’t beat it.
          As for fixing your problem…There is really only one way to fix it right. Roll crimping a bullet without a cannelure is definitely not the answer. These bullets should be pulled, the cases should be resized, re-flared, and then re-seated with a TAPER crimp die. You could purchase a .45 Colt taper crimp seater die, but a properly adjusted .45ACP taper crimp die should work too, if you happen to have one around. Also, you should only taper crimp just enough to remove the flare. Excessive taper crimp can cause lots of problems, but is a common problem with new reloaders.
          As you disassemble them, check the diameter of a few of the bullets after you pull them and make sure that they aren’t undersize for some strange reason…If they are, then pull them and throw the bullets away, they are defective and useless, but I doubt this will be the case. Weigh a couple of the charges to check for consistent charge weight, then collect all the powder in a clean plastic container. A butter dish or lunchmeat container works well for this. Since you are dealing with a mystery powder, write down the charge weight and compare it with your reloading manual. It may not be the exact weight of anything you see in a recipe, but it should be in the general ballpark. IF they are truly factory loads then there is little to be concerned about here…you should be able to rely that they are at least charged properly. It’s just a good idea to double check things. If in doubt, you can always waste the powder and recharge them with something you know. If you want to get rid of the powder, just spread it out on your lawn or garden. It makes good fertilizer.
          When you are ready to start reassembly of the rounds, if you are using a carbide sizer die, then you wont need lubricant. Disassemble your sizer die, remove your decapping pin and wipe them clean of lubricant. If you are using standard steel sizer dies, I would still wipe them clean and then use minimum lubricant, and take care not to get any lubricant inside the case…you don’t want to foul the primers, so don’t get any lubricant anywhere near the primers, inside or out. If the primers get fouled, then you will end up doing a whole lot of work for nothing. Wipe the cases clean immediately after sizing. If you don’t want salvage the primers (not sure why you wouldn’t, but incase you don’t), then soak the primed empty cases in water to kill the primers and then size/decap like normal. Obviously, make sure your cases are bone dry before you re-prime and charge them
          Sorry for my long winded answer, I just want to help you take care of the problem the right way. And I hate to see good components go to waste. Bullets that can move freely in a case is definitely a problem, and if you want to shoot them in a lever gun, it’s a big problem. Take the time to fix them right…bullets should always be very tight in cases…that’s why we need a press to put them in there. If they aren’t, something is very wrong, and you are asking for problems if it’s not fixed, and fixed correctly. If you have any questions, I’d be happy to help.

          • Ryan May 29, 2017, 10:07 pm

            I like your style sir, and believe you to be a tribute to the reloader community.

          • William May 30, 2017, 2:32 am

            I don’t reload 45s yet, but found AKB’s answer to be quite informative. I reload,308,(223,5.56) and 9mm. Haven’t run into any problems and stay on the safe side. Still the AKB answer was interesting and kept me reading it to the end. Thanks. I like ongoing learning and endless days of shooting.

    • DavidInCO May 29, 2017, 10:17 am

      In a revolver, those rounds probably won’t produce an issue, however, as others have said, without seeing them, I can’t say for sure. The caveat is that if they are so loose as to cause the load to squib and lodge in the barrel. I would not use then in a lever rifle where there is spring loaded pressure on the projectile. You may be asking for trouble there.

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